Old cars are a Prius for interstate trips, and an early 2000s Outback for camping/interstate trips where we need to bring more things with. Prius got severely damaged in our parking lot and I used the insurance payout to help with a down payment on a Crosstrek, which will eventually replace the Outback as well.
I feel bad for taking up the (free) parking space, but the cost of ownership of the Outback when infrequently used is something like a $40 insurance premium every six months. That's another benefit of not driving much -- low mileage and safe driver insurance discounts.
And though insurance is officially "tied to the car" it's really tied to the driver; you can't drive more than one car at a time anyway so the third, fourth, tenth vehicle adds less and less.